Jim -- I have that fairly frequently. Between the neck dissection nerve damage and the fibrosis from the radiation, the muscles from upper back, across shoulders, up neck in back and on sides, and in upper chest, can all spasm from time to time, either individually, collectively or in a seemingly endless variation of groupings. :-0

It can sometimes feel like my tongue, ear or jaw actually hurts, but when I check more carefully, it is always an area of muscle spasm. Comes and goes, moves from side to side.

Also, in my particular case, I had two neck surgeries within 9 weeks (spinal fusion first, then neck dissection), some of the sensory nerves in the area still dead, and others are just coming back to life (unfortunately . . )

Sinus headache? Spring in Ohio, my man . . . .:-) Hang in there, buddy. You are doing great!